Overview

3ptWL-cov: Weak-Lensing Covariance Computation

Project Team

Authors:: Sofia Samario-Nava and Alejandro Aviles
Contributors:: Sadi Ramirez Solano (sadi@icf.unam.mx) and Mario A. Rodriguez-Meza
Repository:: Source code and issue tracking

Introduction

3ptWL-cov is a C code for computing the Gaussian contribution to weak-lensing three-point covariance terms in a harmonic basis on the sphere within the Limber approximation. The repository contains a command-line executable, a static C library, a Cython wrapper, and small Python examples.

Installing and Getting Started

After installing GSL, install the Python interface from PyPI:

python3 -m pip install wlcovpy

This builds and installs wlcovpy without a separate make command.

The optional source build creates the executable wlcov, the static library libwlcov.a, and the Python extension wlcovpy:

make clean
make PYTHON=python3 all

To check that the code runs, type from the repository root:

./wlcov clsfile=tests/input/Cls_ep2.txt rootDir=Output_quick \
   ellmax=25 ppp=4 Nr=8 rmin=0.00232711 rmax=0.02 \
   verbose=0 verbose_log=0

The run writes a used-values parameter file under Output_quick and prints the numerical integration results to standard output.

Documentation Builds

From the repository root, install documentation dependencies and build the HTML, man, and PDF outputs:

python3 -m pip install --user -r docs/requirements.txt
cd docs

make html
make man
make latexpdf

The generated artifacts are written to:

docs/_build/html/index.html
docs/_build/man/wlcov.1
docs/_build/latex/3ptWL-cov.pdf

The legacy hand-written man page is also kept in docs/man and can be converted to HTML with:

cd docs/man
./makehtml.sh

Configuration

Build-time switches are controlled by Makefile_settings and Makefile_machine. The most important settings are USEGSL, OPENMPMACHINE, and ADDONSON. Runtime parameters can be supplied as name=value command-line tokens or in a parameter file.

Python

The Python wrapper is imported as:

from wlcovpy import wlcov

A compact wrapper example is available in docs/examples/python_wrapper.py.

License

3ptWL-cov is distributed under the MIT license. If you use this program in research that results in publications, please cite Sofia Samario et al., arXiv:2506.19811, and record the code version, compiler, GSL version, and runtime configuration used for the analysis.